Spectrally sensitized silver halide photographic emulsion

ABSTRACT

A silver halide photographic emulsion sensitized with the combination of (1) at least one dimethine merocyanine dye wherein the carbon atom at the 2-position of an oxazole nucleus bearing an alkyl group containing a sulfo or a carboxyl group on the nitrogen atom at the 3-position thereof and the carbon atom at the 5-position of a 2-thiohydantoin nucleus bearing a hydrogen atom or an alkyl group on the nitrogen atom at the 1- and 3positions thereof are connected with each other through a dimethine chain, and (2) at least one of a J-band type carbocyanine dye wherein a sulfo group-containing alkyl group is attached to the nitrogen atom at the 3-position of a naphthothiazole nucleus, a naphthoselenazole nucleus, a benzothiazole nucleus or a benzoselenazole nucleus and the carbon atom at the 2-position is attached to mesoalkyl-substituted trimethine chain is disclosed.

United States Patent [1 1 Shiba et al.

[ SPECTRALLY SENSITIZED SILVER HALIDE PHOTOGRAPHIC EMULSION [75]Inventors: Keisuke Shiba; Akira Sato; Akira Ogawa, all of Kanagawa,Japan [73] Assignee: Fuji Photo Film Co., Ltd.,

Kanagawa, Japan [22] Filed: Sept. 5, 1972 [21] Appl. No.: 286,396

[30] Foreign Application Priority Data Sept. 2, 1971 Japan 46-67712 [52]US. Cl 96/126, 96/137, 96/140 [51] Int. Cl G03c 1/14 [58] Field ofSearch 96/126, 140

[56] References Cited UNITED STATES PATENTS 3,615,633 10/1971 Brooks96/126 3,671,260 6/1972 Oftedahl et al.. 96/126 3,703,377 11/1972Sakazume et al.... 96/140 3,711,288 l/l973 Sato et al 96/140 [451 Sept.24, 1974 Primary Examiner-J. Travis Brown Attorney, Agent, orFirmSughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A silverhalide photographic emulsion sensitized with the combination of (1) atleast one dimethine merocyanine dye wherein the carbon atom at the2-position of an oxazole nucleus bearing an alkyl group containing asulfo or a carboxyl group on the nitrogen atom at the 3-position thereofand the carbon atom at the 5- position of a 2-thiohydantoin nucleusbearing a hydrogen atom or an alkyl group on the nitrogen atom at the 1-and 3-positions thereof are connected with each other through adimethine chain, and (2) at least one of a J-band type carbocyanine dyewherein a sulfo group-containing alkyl group is attached to the nitrogenatom at the 3-position of a naphthothiazole nucleus, a naphthoselenazolenucleus, a benzothiazole nucleus or a benzoselenazole' nucleus and thecarbon atom at the 2-position is attached to mesoalkylsubstitutedtrimethine chain is disclosed.

17 Claims, 6 Drawing Figures BLWFLBSZ PATENTEUSEPZMSM 500 WAVELENGTH(nm) L 0 WAVELENGTH (n m) WAVELENGTH (nm) WAVELENGTH (nm) WAVELENGTH(nm) SPECTRALLY SENSITIZED SILVER HALIDE PHOTOGRAPHIC EMULSIONBACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The presentinvention relates to a panchromatically and spectrally sensitized silverhalide photographic emulsion, and more particularly, it relates to asilver halide emulsion providing especially high red sensitivity withless stain and excellent contrast, wherein the synergistic effect causedby the combination of a special type of mercyanine dye and special typeof red sensitive carbocyanine dye having a tendency to form J- band isutilized.

2. DESCRIPTION OF THE PRIOR ART It has been known to use various typesof merocyanine dyes for the spectral sensitization of a silver halidephotographic emulsion. The spectrally sensitizing action obtained,especially in the merocyanine dyes, depends upon the properties of theemulsion used, such as the halogen composition, the crystal habit, thegrain size, the pAg and the pH of the emulsion, and the manner ofchemical sensitization, as well as the chemical structure of thesensitizing dyes and the physical properties thereof. Most of themerocyanine dyes in a single employment adsorb directly on the silverhalide grains in the emulsion to function as a M-band type of spectralsensitizer. When used together with cyanine dyes, most of themerocyanine dyes tend to destroy the J- aggregate formed by the cyaninedyes, and hence they have a tendency to deteriorate the spectrallysensitizing action of the cyanine dyes.

It is extremely useful to use the cyanine dyes in the J-aggregate statefor the sensitization of a silver halide photographic emulsion in thered wavelength region of from 590 to 690 nm. Especially, it is usefulfor providing an emulsion with high contrast. This is based on the factthat, generally speaking, the cyanine dyes having shorter lightabsorption wavelength in an alone state are chemically stable and, in a.l-aggregation state, they then absorb light of longer wavelengths byseveral tens of nanometers in spite of the short methine chain. A J-aggregate can provide narrow light absorption and, in addition, canprovide light absorption in the longer wavelength region than M-band byseveral tens of nanometers.

However, the J -aggregate formed by the cyanine dyes tend to bedestroyed also by co-existing dyestuffs, chemical sensitizers,stabilizing agents, fog inhibitors, surface active agents, hydrophilicsynthetic polymers, color couplers, development accelerators andinhibitors.

In most cases, panchromatic sensitization of a silver halide emulsioncan be attained by two or more of the sensitizing dyes. In this case, itis extremely important to develop useful special combinations whereinthe spectral sensitizations with the individual sensitizing dye can beenhanced by each other.

Incomplete removal of the sensitizing dyes used from a light-sensitivematerial during the step of development processing of thelight-sensitive material will cause a staining of the resulting images.On the other hand, in order to provide a strong spectrally sensitizingaction, the sensitizing dyes must be very strongly adsorbed on thesilver halide grains. Generally speaking,

in the case of the merocyanine dyes, the direction of the adsorptionproperty and the direction of the reduction in stain are opposite witheach other.

An object of the invention is to improve the abovedescribed defects.

That is, an object of the invention is to provide a panchromaticallysupersensitized light-sensitive material with excellent contrast forindustrial recording.

Another object of the invention is to provide a silver halidephotographic emulsion having an especially high gamma and high redsensitivity.

A further object of the invention is to provide merocyanine dyes whichact as supersensitizers for the pan chromatically sensitizingcarbocyanine dyes and to provide high ortho sensitivity with less stain.

A still further object of the invention is to provide a silver halidephotographic emulsion which provides images having less fog andexcellent grain property.

SUMMARY OF THE INVENTION It has now been found that the above-describedobjects of the invention can be accomplished as described hereinafter,whereby the above stated defects can be improved. That is, the objectsof the invention have been attained by the combined use of at least oneof the dimethine merocyanine dyes wherein the carbon atom at the2-position of an oxazole nucleus bearing an alkyl group containing asulfo or a carboxyl group on the nitrogen atom at the 3-position thereofand the carbon atom at the 5-position of a 2-thiohydantoin nucleus areconnected with each other through a dimethine chain, preferably at leastone of the dyes represented by the following general formula (I);

or 0 O OM wherein R and R each represents a hydrogen atom, a lower alkylgroup, an aryl group or R and R may be combined to form an aromatic ringof the benzene series or of the naphthalene series, R and R eachrepresents a hydrogen atom, an alkyl group, L and L each represents amethine group, A represents a divalent aliphatic group, and M representsa cation, and at least one of the J-band forming carbocyanine dyescomprising two cyanine nuclei selected from the group consisting of anaphthothiazole, a naphthoselenazole, a benzothiazole and abenzoselenazole nucleus, the nitrogen atom at the 3 -position of atleast one nucleus being attached to a sulfo group and the carbon atom atthe 2 -position being attached to a mesoalkyl substituted trimethinechain, preferably at least one of the dyes represented by the followinggeneral formula (II);

Wherein Y and Y each represents a sulfur atom or a selenium atom, Brepresents a lower alkyl group having 3 or less carbon atoms, Z and Zeach represents the atoms necessary to complete an aromatic ring of thebenzene series or of the naphthalene series. R and R each represents alower alkyl group or a sulfo group containing alkyl group, and whereinat least one of R and R is a sulfo group containing alkyl group capableof forming a betaine structure, in a silver halide photographicemulsion.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 6 are spectrogramscomparatively shown in order to explain the invention in detail.

DETAILED DESCRIPTION OF THE INVENTION As described above, in the abovegeneral formula (I), R, and R represent hydrogen atoms, lower alkylgroups preferably having up to 4 carbon atoms (e.g., methyl, ethyl,etc.), aryl groups (e.g., phenyl, substituted phenyl wherein thesubstituent is a alkyl group, a sulfo group and the like, such as tolyland sulfophenyl, etc.), or when taken together, R and R represent theatoms capable of forming an aromatic ring of the benzene series (e.g., abenzoxazole nucleus, substituted benzoxazole nucleus wherein thesubstituent is an alkyl group, a halogen atom, a hydroxyl group, analkoxy group, an aryl group,, an acetoxy group and the like, such as aS-methylbenzoxazole nucleus, a 6- methylbenzoxazole nucleus, a5-chlorobenzoxazole nucleus, a S-hydroxybenzoxazole nucleus, a 5-methoxybenzoxazole nucleus, a 5-chloro-6-methylbenzoxazole nucleus, a5-phenylbenzoxazole nucleus, and a S-acetoxybenzoxazole nucleus, etc.)or an aromatic ring or the naphthalene series, (e.g., a-naphthoxazolenucleus, B, B-naphthoxazole nucleus, B-naphthaxazole nucleus, etc.), Rand R represent hydrogen atoms, or alkyl group [(e.g., methyl, ethyl,2-propenyl, hydroxyalkyl (e.g., hydroxyethyl), acetoxyalkyl (e.g.,acetoxypropyl), aminoalkyl (e.g., aminoethyl, dimethylaminoethyl),carboxyalkyl (e. g., carboxyethyl), sulfoalkyl (e.g., 3-sulfopropyl,3-sulfobutyl), aralkyl (e.g., benzyl), etc., the alkyl moiety thereofbeing preferably a lower alkyl group having from 1 to 4 carbon atoms],

- L; and Is; represent methine groups (wherein W represents, forexample, an alkyl (e.g., methyl), hydroxyalkyl (e.g., hydroxypropyl),carboxyalkyl (e.g., carboxyethyl), aryl (e.g., carboxyphenyl), alkoxy(e.g., methoxy group), etc.)), A represents a divalent aliphatic group(e.g., ethylene, propylene, butyl- 'ene, isopropylene, propenylene, thegroups described in Zeitschrift fur wissenschaftliche Photographie, vol.63, pp.l49 pp. 158 (1967), written by E..l. Poppe, etc.), M represents acationic group capable of forming a sulfonate or a carboxylate (e.g., asodium ion, an ammonium ion, a hydrogen ion, a thiouronium ion, etc.).

In the above-illustrated general formula (II), Y, and Y represent sulfuror selenium atoms, B represents a lower alkyl group having 3 or lesscarbon atoms (e.g., methyl, ethyl, propyl, etc.), Z and 2 represent theatoms necessary to complete an aromatic ring of the benzene series(e.g., benzothiazole, substituted benzothiazole wherein the substituentis a halogen atom, an alkoxy group, an alkyl group and the like, such as5- chlorobenzothiaz'ole. 5.6-dichlorobenzothiazole, 5-methoxycarbonylbenzothiazole, 5- methoxybenzothiazole.S-bromobenzothiazole. and 5- methylbenzothiazole, benzoselenazole,substituted benzoselenazole wherein the substituent is an alkyl group,an alkoxy group, a hydroxy group, an aryl group, and the like, such asS-methylbenzoselenazole, 5-ethoxybenzoselenazole,5-hydroxybenzoselenazole, S-phenylbenzoselenazole nucleus, etc.) or anaromatic ring of the naphthalene series (e.g., naphthothiazole,naphthoselenazole nucleus, etc.), R and R represent an alkyl group(e.g., methyl, ethyl, propyl, propenyl, hydroxyalkyl (e.g.,hydroxyethyl), amidoalkyl (e.g., amidoethyl), acetoxyalkyl (e.g.,acetoxypropyl), carboxyalkyl (e.g., carboxyethyl, carboxypropyl group),etc., the alkyl moiety thereof being a lower alkyl group havingpreferably from 1 to 6 carbon atoms), or a sulfo group-containing alkylgroup (e.g., a sulfoethyl, sulfopropyl, 3sulfobutyl, 4-sulfobutyl,2-(3-sulfopropoxy )ethyl, 2-[ 3-sulfopropoxy )ethoxy lethyl,sulfatopropyl group, the groups described in Zeitschrift furwissenschaftliche Photographic vol. 63, pp. 149 158 (1969), written byE. .1. Poppe, etc.), at least one of R and R being a sulfogroup-containing alkyl group which is capable of forming a betainestructure.

A first characteristic of the invention is due to the chemical structureof the merocyanine dyes used in the invention.

The chemical structure of the merocyanine dyes used in the invention ischaracterized by the oxothiohydantoin dimethine merocyanine, especiallyin the connection of the nitrogen atom in the oxazole nucleus to analkyl group containing a sulfo group, and in the special combination ofan oxazole nucleus and a thiohydantoin nucleus in one molecule.

Generally speaking, the oxothiohydantoin dimethine merocyanine dyes aredisclosed in US. Pat. Nos. 2,493,748; 2,519,001; and 3,480,439; JapanesePatent Publication Nos. 18105/7]; 18106/71; 18108/71; and 2606/68;Belgian Patent Nos. 648,068; 701,921; and

718,63 l; and French Patent No. 1,451,598.

The merocyanine dyes in accordance with the inven tion have thecharacteristics that, when used independently, they provide M-band typehigh sensitivity in the green wavelength region without forming fog, andthat less stains are formed after development processing.

The merocyanine dyes described in US. Pat. No. 2,493,748 relate tomerocyanine dyes having an acidic group in a keto nucleus, which ismainly a rhodanine nucleus or an oxazoledione nucleus, and there is nospecific description of the presence of a thiohydantoin nucleus havingsulfo group. Accordingly, the dyes described in the US. Pat. No.2,493,748 are absolutely different from the dye of the invention.

The merocyanine dyes described in U.S. Pat. No. 2,519,001 relates tomerocyanine dyes having a sulfoalkyl group or a carboxy-alkyl group atthe cyanine nucleus thereof, but nothing is described therein withrespect to the oxothiodydantion dimethine merocyanine dyes in accordancewith the invention and the effects of the invention.

In the merocyanine dyes of the invention, a sulfo group-containing alkylgroup is attached to the nitrogen atom in a basic oxazole nucleus, andthe dyes adsorb on the silver halide grains better than the merocyaninedyes described in US. Pat. No. 2,493,748, are much less adverselyaffected by the co-presence of other additives, and tend to provide highsensitivity. Furthermore, they change very little in sensitivity due toa'variation in the substituents at the l and the 3- positions of a2-thiohydantoin nucleus (e.g., methyl,- propyl, phenyl, benzyl, etc.),and tend to provide high sensitivity with substituents having a smallsize such as a methyl, an ethyl group etc. and derivatives thereof. Ofcourse, the merocyanine dyes in accordance with the invention have theadvantage that they form less stains.

The object of the invention of French Patent No. 1,451,598 is to formJ-band by introducing specific alkyl groups into the l-and the3-positions of a 2- thiohydantoin nucleus to utilize the J-band. In thisconnection, if an n-propyl group or an n-butyl group is attached toeither the lor the 3-position of the 2- thiohydantoin nucleus, stainstend to increase, which is against the object of the present invention.

A second characteristic of the invention (which is a most importantpoint of the invention) is that, when the merocyanine dyes and thecarbocyanine dyes in accordance with the invention are used incombination, the gamma in the wavelength region sensitized with thecarbocyanine dyes is markedly enhanced and a high sensitivity can beobtained without degrading the sensitivity in the wavelength regionsensitized with the merocyanine dyes. It should be noted that the effectof the merocyanine dyes to raise the gamma in the red sensitivewavelength region caused by the cyanine dyes has not so far been known.A detailed description thereof will be given in the specific examplesset forth hereinafter.

US. Pat. No. 2,430,558 discloses the fact that combination of theso-called acid merocyanine dyes containing a sulfo or a carboxyl groupat a keto nucleus with the basic trimethine cyanine dyes producesupersensitization. However, the compounds described in the above patentspecification, being merocyanine dyes or trimethine cyanine dyes, areabsolutely different in chemical structure from the dyes in accordancewith the invention, and, in addition, there is no specific descriptionin the above patent specification of a merocyanine dye having a2-thiohydantoin nucleus, much less of the effect of the enhancement ofthe sensitivity and the provision of contrast in the red supersensitizedwavelength region, and a reduction in stains.

A third characteristic of the invention lie in the chemical structure ofthe carbocyanine dyes. The merocyanine dyesin accordance with theinvention do not provide all the carbocyanine dyes with above-describeduseful effects, but provide only certain carbocyanine dyes of theinvention with such effects.

The merocyanine dyes of the invention do not act as supersensitizers ofthe trimethine cyanine dyes disclosed in US. Pat. No. 2,430,558, and, inmany cases, on the contrary they degrade the red sensitivity, asdescribed in the examples given hereinafter.

No description of the special effect produced by the combined use of thedyes in the present invention can be found in Japanese PatentPublication Nos. 2606/68; 18105/71; 18106/71; and 18108/71; BelgianPatent Nos. 701,921; 716,831; and 690,096; British Patent No. 1,112,036;and US. Pat. No. 3,480,439, either.

Suitable silver halide emulsions which can be used in the invention aremixed silver halide emulsions with any mixing ratio of chlorine ion.bromine ion or iodine ion. The equivalent circular diameter of thegrains ranges from 0.04 to 2 microns.

The degree of the effect of the invention greatly depends upon theproperties of the silver halide emulsion, and a silver chlorobromideemulsion or a silver chlorobromoiodide emulsion containing at least 30mol percent of chlorine ion is especially useful. In addition, for theobjects of the invention, preferably a silver halide photographicemulsion containing grains whose grain diameter distribution mode isless than 0.8 p. is especially useful. Furthermore, silver halide grainsin which at least percent by weight have a crystal habit with a (1,0,0)face are preferable. The emulsions to be used in the invention arepreferably chemically sensitized using reduction sensitization (U.S.Pat. Nos. 2,518,698, 2,419,974, 2,983,610, etc.), sulfur sensitization(U.S. Pat. Nos. 1,574,944, 2,278,947, 2,440,206, 2,410,689, 3,189,458,3,415,649, etc.) or gold sensitization (U.S. Pat. Nos. 2,540,085,2,597,856, 2,597,915, 2,399,083, etc.). It is especially preferable toemploy the group llb metal salts (e.g., a cadmium salt (e.g., nitrate,chloride), a mercury salt, (e.g., chloride, etc.), the group Vlll metalsalts (e.g., a rhodium salt, an iridium salt, a nickel salt, etc. refer,for example, to US. Ser. No. 219,047/72) or the group lVb metal salts(e.g., a lead salt (e.g., nitrate, chloride), etc.). The group llb metalsalts (e.g., cadmium chloride, zinc chloride, etc.) may be used as well.

Typical and .specific examples of dyes which can be used in theinvention will be illustrated hereinafter. This, however, is notintended to limit the invention in any way.

HmCOOH The chemical structural formulae of the comparative dyes used inthe experiments conducted to explain the objects of the invention aregiven below.

Examples including comparative experiments of the present invention willbe illustrated hereinafter.

EXAMPLE 1 A silver chlorobromide emulsion was prepared in theconventional manner. The chlorine ion content of the grains was 83 molpercent, and the mode of grain diameter distribution was 06 pt. Most ofthe grains had the (100) face. The silver content of the resultingemulsion was 1.3 mol/kg. 500 grams of the emulsions were weighed out ineach pot and heated to 40C to melt the emulsions. To the emulsions werefurther added 20 cc of a l M CdCl solution. While stirring, each dyegiven in Table l was added to the emulsion as 21 methanol solution.After leaving for 15 minutes while stirring at 40C, 10 cc of a 1 percentaqueous solution of sodium dodecylbenzenesulfonate and 10 cc of a 2percent aqueous solution of 2,4-dichloro-6-hydroxy-S-triazine were addedthereto. Each of the resulting emulsions was then applied to a celluloseacetate film in a dry thickness of about 4 pt to obtain samples. Each ofthe resulting samples was slit into a strip and wedgewise exposed tolight from tungsten light source of 2854K through a Wratten N058B greenfilter, a Wratten N025A red filter or a SC-42 yellow filter (made by theFuji Photo Film Co., Ltd), then developed for 20 minutes in a developerprepared by diluting the developer having the following composition withwater in lzl by volume ratio.

Composition of the Deveioper Sodium Carbonate Hydrate g PotassiumBromide 2 g Water to make I000 cc On the other hand, the spectrogram ofeach sample 10 was determined using a spectrograph containing areflection-type diffraction grating. The results obtained are shown bythe curves 1 to 11 in FIGS. 1 to 6.

10 In order to demonstrate the effective influence of the combined useof the merocyanine dyes and the carbocyanine dyes of the invention onthe gamma in the red sensitive wavelength region, the followingsensitometry was conducted.

Wedgewise exposure was conducted using a monochromatic light sourcecorresponding nearly to the sensitization maximum in the red sensitivewavelength region, and the same development, fixation and measurement ofdensity as described above were effected to obtain H and D curves. Theslope of the straight line por- "Q" tssfiwaidsit m nsd which wi li rd ith Table 1 No. Merocyanine Carbocyaninc Photographic Spectro- Dye UsedDye Used Characteristics gram cc cc (mol con- (mol con- & Sg Sv l-ogcentration) centration) 1 (1C) 80 80 83 0.26

( FIG. 1

120 100 100 0.27 Curve 1 160 i 117 117 0.33 (11A) 100 40 0.22

(5Xl0") (FIG. 1)

40 112 0.22 Curve 2 80 107 42 0.25 (1C) 40 (11A) 40 145 80 100 0.19 8040 145 100 126 019 FIG. 1 120 40 135 100 132 0.14

Curve 3 2 (B) 80 40 44 0.27

Curve 4 160 35 31 0.35 (A) 20 107 45 0.25 6x10) FIG. 2 40 118 0.18

Curve 5 141 66 0.16 (B) 40 (A) 40 40 56 0.28 80 do. 42 40 50 0.20

FIG. 2 120 do. 31 32 40 0.20

Curve 6 3 (B) 40 (11A) 40 71 40 61 0.20 80 do. 60 43 57 0.20

FIG. 3 120 do. 35 37 44 0.10

Curve 7 4 (1C) 40 (A) 40 117 63 0.30 80 do. 107 85 0.29

FIG. 4 120 do. 83 104 120 0.29

. Curve 8 5 (11C) 40 25 16 0.20 FIG. 5

(1Xl0"") Curve 9 8O 32 20 0.21 (1C) 80 (11C) 40 72 94 110 0.15

FIG. 5 do. 100 100 132 0.25

Curve 10 6 (B) 80 (11C) 40 40 42 60 0.20

. FIG. 6

Curve 11 Too small to measure accurately.

gamma value. The results obtained are shown in Table It is believed thatthe excellent advantages of the in- 2. vention as enumerated below canbe fully understood Table 2 No. Merocyanine Carbocyaninc Wavelengthammzi Dye Used Dye Used of Exposure CC CC nm (mol con (molconcentration) centrution) 7 ("A1 680 2.l4

do. 3.22 80 do. 3.13 (IC) 40 (2Xl0) (HA) 40 do. 3.64 80 do. do. 4.0l 120do. do. 4.30 8 (B) 40 (2Xl0 (NA) 40 680 2.88 80 40 do. 280 I20 do. do.2.08 9 (A) 20 (SXHT) 680 0.88 40 do. l.l4 80 do. 2.72 (lC) 40 (A) 40 do.l 20 80 do. do. E38 120 do. do. (1.53 10 B 40 (A) 40 680 1.22

80 do. do. 120 do. do. ll (llC) 40 (1Xl()"] 650 1.80 80 do. L72 (1c) 40(11c) 40 do. ms 80 do. do. 156

* Too small to measure accurately.

from the above results. That is,

l. a silver halide photographic emulsion with excel lent contrast can beobtained;

cyanine dyes in accordance with the invention, the var- 35 2. highpanchromatic sensitivity, especially high red iation in sensitivity dueto the change of the substituent sensitivity can be obtained; at thenitrogen atom in the thiohydantoin nucleus is re- 3. stains can bereduced; duced by the introduction of the sulfo group-containing 4. thefogging level can be maintained at a low level alkkyl group into theoxazole nucleus. by the combination of at least two dyes; and the Table3 No. Merocyanine Sy Fog Stain Dye Uscd EXAMPLE 2 cc A silverchlorobromoiodide was prepared in the conmoico ventional manner (thechlorine ion content: 30 mo] mm0) ercent. the i d'n ion 11 12 1c) 120100 0.27 Nothing p O I CO 2 mol pelcem) 500 (zxmq) grams of theemulsions were weighed out in each pot 160 117 0.33 do and heated to 40Cto melt the emulsions. While stir- (IF) 1 2a, Nmhmg ring, each dye shownin Table 4 was added to the emul- 160 120 0.30 do. sion as a methanolsolution. After leaving for 10 min- 14 (16) 1 f3 90 Nmhmg utes whilestirring at 40C, 10 cc of a 1 percent aqueous 160 85 032 do solution ofsodium dodecylbenzenesulfate and 10 cc of 15 (B) 120 44 Nothing :1 2percent aqueous solution of 2,4-dichloro-6- 12% 3| 035hydroxy-S-triazine were added thereto. Each of the rel6 c) 120 100 0.30Extremely sulting emulsions was then applied to a cellulose ace- (2)60)great 160 HO 034 do tate film in a dry thickness of about 4 u to obtainsam 17 (D) 120 22 0.30 do. ples.

012%) 10 0 d Sensitometry was conducted according to Example I J toobtain the results given in Table 4.

Table 4 No. Mcrocyanine Carbocyanine Photographic Characteristics DycUsed Dye Used w w SrSg FOa (mol con- (mol concentration! ML i2 (1A) 0.23

No Merocyanine carbocyanine Photographic Characteristics Dye Used DyeUsed cc. cc. (mol con- (mol con- Sr SE F03 centration) centration)(5Xl0") (11B) 40 (SXIO'U 160 0.22 (1A) 80 (118) do. 170 112 0.23 13 (1B)80 (l l0") 71 0.23 80 80 0.25 (18) 8O (11D) 40 96 120 0.29 14 (ID) 80(llE) 20 (1 l0') 56 50 0.17 40 117, 98 0.22 80 210 141 0.20 (1D) 80 (NE)40 120 152 0.19 (1F) 80 (2X10 (11E) 40 117 152 0.22 120 do. 117 178 0.2116 (IE) 80 (2Xl0") 126 0.26 120 132 0.29 160 142 0.35 (11F) 40 (mo- 8331 0.22 (1E) 80 (HF) 40 100 132 0,25 120 do. 122 152 0.35

' Too small to measure accurately.

EXAMPLE 3 as special anti-optical sensitization is not produced.

Of the samples obtained in Example 1, the sample used in Experiment No.l and No. 5 were wedgewise exposed as described in Example 1 anddeveloped for -2 minutes at C using an infectious developer which can beused for lithographic materials. Thus, images with a high panchromaticsensitivity, less stains and sharp toe-gradation could be obtained (see,for example, the paper by J.A.C. Yule reported in Journal of FranklinInstitute, vol. 239, pp.22l230 (1945).

Composition of the Developer Water (about C) 500 cc Anhydrous SodiumSulfite 30 g Paraformaldehyde 7.5 g Acid Sodium Sulfate 2.2 g Boric Acid7.5 g Hydroquinone 22.5 g Potassium Bromide 1.6 g Water to make 1000 ccThe sensitizing dyes used in the invention can be used preferably in anamount of from 1 X 10 mol to 5 X 10 mol per mol of silver depending uponthe properties of silver halide emulsion used. The molar ratio of thecarbocyanine dyes to the merocyanine dyes used in the invention ispreferably from H 10 to l to 5 to l. The sensitizing dyes can be addedas solution of a watermiscible organic solvent (e.g., methanol, ethanol,pyridine, acetone, cellosolve, etc.) or as an aqueous solution. Inaddition, conventional procedures employed by those skilled in the artcan be applied.

The sensitizing dyes used in the invention can be used together withother sensitizing dyes such as the simple merocyanine dyes and dimethinemerocyanine dyes included in the description of US. Ser. No. 236175(1972), the monomethine cyanine dyes included in the description of US.Ser. No. 219047 1972), trimethine cyanine dyes and pentamethine cyaninedyes, as long The complete emulsions prepared by the invention areapplied to an appropriate support such as films, e.g., cellulose acetatefilms, cellulose acetate butyrate films, polyester films and otherplastic films, papers such as baryta paper, polyolefin-coated papers,paper substitutes; glass plates; plastic plates, and the like.

The photographic effect of the photographic materials produced using thephotographic emulsion of the invention is the same whether processed bycontinuous processing using an autodeveloping machine or using manualdevelopment processing as conventionally conducted.

The silver halide photographic light-sensitive materials obtained in theinvention are especially useful for photographic arts materials,facsimile materials, microfilm materials, materials for COM system, asuper-fine grain material for the production of 1C or LS1 or forholography, wherein especially a panchromatic sensitivity and acontrasty gradation are required.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and 'scope thereof.

What is claimed is:

l. A silver halide photographic emulsion sensitized with the combinationof l at least one dimethine merocyanine dye wherein the carbon atom atthe 2- position of an oxazole nucleus bearing an alkyl group containinga sulfo or a carboxyl group on the nitrogen atom at the 3-positionthereof and the carbon atom at the 5-position of a 2-thiohydantoinnucleus bearing a hydrogen atom or an alkyl group on the nitrogen atomat the 1- and 3-positions thereof are connected with each other througha dimethine chain, and (2) at least one of a J-band type carbocyaninedye comprising two cyanine nuclei joined by a trimethine chain selectedfrom the group consisting of a naphthothiazole nucleus, anaphthoselenazole nucleus, a benzothiazole nucleus or a benzoselenazolenucleus and the carbon atom at the 2-position of two of said cyaninenuclei is attached to a mesoalkyl-substituted trimethine chain atopposite ends of said chain, at least one of said cyanine nuclei havinga sulfo group-containing alkyl group attached to I the nitrogen atom atthe 3-position thereof.

2. The silver halide photographic emulsion as claimed in claim 1,wherein saidd dimethine merocyanine dye is represented by the followinggeneral formula;

wherein R, and R each represents a hydrogen atom, a lower alkyl group oran aryl group, or, when taken together, R, and R represent the atomscapable of forming an aromatic'ring of the benzene series or thenaphthalene series, R and R each represents a hydrogen atom or an alkylgroup, L, and L each represents a methine group, A represents a divalentaliphatic group and M represents a cation group, and said carbocyaninedye is represented by the following general formula;

wherein Y, and Y each represents a sulfur atom or a selenium atom, Brepresents a lower alkyl group having 3 or less carbon atoms, Z, and Zeach represents the atoms necessary to complete an aromatic ring of thebenzene series or the naphthalene series, R and R each represents alower alkyl or sulfo-containing alkyl group, at least one of R and Rbeing a sulfoa a nin alkyl r 3. The silver halide photographic emulsionas claimed in claim 1, wherein said emulsion containssilver'chlorobromide or silver chlorobromoiodide grains whose chlorineion content is at least 30 mol percent, the mode of the grain diameterdistribution is 0.8 p. or less than 0.8 u, and at least 80 percent byweight of the grains have the crystal habit with a (1,0,0) face.

4. The silver halide photographic emulsion as claimed in claim 1,wherein the emulsion additionally contains a group Ilb metal salt, agroup VIII metal salt or a group lVb metal salt.

5. The silver halide photographic emulsion as claimed in claim 2,wherein said lower alkyl group for R, and R, is a methyl group or anethyl group, wherein said aryl group for R, and R is a phenyl group, atolyl group, or a sulfophenyl group, wherein said aromatic ring of thebenzene series formed by R, and R forms a benzoxazole nucleus, or asubstituted benzoxazole nucleus wherein the substituent is an alkylgroup, a halogen atom, a hydroxyl group, an alkoxy group, an aryl groupand an acetoxy group, and wherein said aromatic ring of the naphthaleneseries formed by R, and R forms an a-naphthoxazole nucleus, at[3,B-naphthoxazole nucleus, or a B-naphthoxazole nucleus, wherein saidalkyl group for R and R, is a methyl group, an ethyl group, a Z-propenylgroup, a hydroxyalkyl group, an acetoxyalkyl group, an aminoalkyl group,a carboxyalkyl group. a sulfoalkyl group, or an aralkyl group, whereinsaid methine groups for L, and L represent =CH- or in which W is analkyl group, a hydroxyalkyl group, a carboxyalkyl group, an aryl groupor an alkoxy group, wherein A is an ethylene group, a propylene group, abutylene group, an isopropylene group, or a propenylene group, wherein Mis a sodium ion, an ammonium ion, a hydrogen ion, or a thiouronium ion,wherein the ring of the benzene series formed by Z, and Z is ahenzothiazole nucleus, a substituted benzothiazole nucleus wherein thesubstituent is a halogen atom, an alkoxy group, or an alkyl group, abenzoselenazole nucleus, or a substituted benzoselenazole nucleuswherein the substituent is an alkyl group, an alkoxy group, a hydroxygroup, or an aryl group and wherein the aromatic ring of the naphthaleneseries formed by Z, and Z is a naphthothiazole nucleus or anaphthoselenazole nucleus, wherein the alkyl group for R and R is amethyl group, an ethyl group, a propyl group, a propenyl group, ahydroxyalkyl group, an amidoalkyl group, an acetoxyalkyl group, or acarboxyalkyl group, and wherein said sulfo group-containing alkyl groupfor R and R is a sulfoethyl group, a sulfopropyl group, a 3- sulfobutylgroup, a 4sulfobutyl group, a 2-(3-sulfo- -propoxy)ethyl group, a2-[2-(3-sulfopropoxy)ethoxy] ethyi group, or a sulfato propyl group,

6. The silver halide photographic emulsion as claimed in claim 1 whereinsaid sensitizing dyes are each present in said emulsion in an amountranging from I X 10 mol to 5 X 10" mol per mol of silver and wherein themolar ratio of said carbocyanine dye to said merocyanine dye ranges fromI! 10:1 to 5:1.

7. A light sensitive photographic element comprising a support having atleast one layer coated thereon of the silver halide photographicemulsion of claim 1.

8. A light sensitive photographic element comprising a support having atleast one layer coated thereon of the silver halide photographicemulsion of claim 2.

9. The light sensitive photographic element as claimed in claim 7wherein said support is a synthetic resin film, a paper, a polyolefincoated paper, a paper substitute, a glass plate, or a plastic plate.

10. The silver halide photographic emulsion as claimed in claim 2wherein said dye of the general formula II is selected from the groupconsisting of impos C-OHzC-CH:

CgHs (51103803 gHs and wherein said dye of the general formula I isselected from the group consisting of CZH5 N C=CHCH=Z/ Q: N/(Hz)3SO3HN(C2H5)a (I3 H G=CHCH=E/ HmsoafiNwzHm (]J 40 and CgHs ,/O N

C:CHCH:C

N HmSOaNa 11. The silver halide photographic emulsion as claimed inclaim 2, wherein Y and Y each represents a sulfur atom.

12. The silver halide photographic emulsion as claimed in claim 2,wherein Y and Y each represents a selenium atom.

13. The silver halide photographic emulsion as claimed in claim 2,wherein Z and Z each represents the atoms necessary to complete anaromatic ring of the benzene series 14. The silver halide photographicemulsion as claimed in claim 2, wherein Z and Z each represents theatoms necessary to complete an aromatic ring of the naphthalene series.

15. The silver halide photographic emulsion as claimed in claim 2,wherein the substituent on A is $0 M.

16. The silver halide photographic emulsion as claimed in claim 2,wherein the substituent on A is COOM.

17. The silver halide photographic emulsion as claimed in claim 1,wherein the sensitizing dye combination consists essentially of at leastone of said dimethine merocyanine dyes and at least one of said J-bandtype carbocyanine dyes.

2. The silver halide photographic emulsion as claimed in claim 1,wherein saidd dimethine merocyanine dye is represented by the followinggeneral formula;
 3. The silver halide photographic emulsion as claimedin claim 1, wherein said emulsion contains silver chlorobromide orsilver chlorobromoiodide grains whose chlorine ion content is at least30 mol percent, the mode of the grain diameter distribution is 0.8 Mu orless than 0.8 Mu , and at least 80 percent by weight of the grains havethe crystal habit with a (1,0,0) face.
 4. The silver halide photographicemulsion as claimed in claim 1, wherein the emulsion additionallycontains a group IIb metal salt, a group VIII metal salt or a group IVbmetal salt.
 5. The silver halide photographic emulsion as claimed inclaim 2, wherein said lower alkyl group for R1 and R2 is a methyl groupor an ethyl group, wherein said aryl group for R1 and R2 is a phenylgroup, a tolyl group, or a sulfophenyl group, wherein said aromatic ringof the benzene series formed by R1 and R2 forms a benzoxazole nucleus,or a substituted benzoxazole nucleus wherein the substituent is an alkylgroup, a halogen atom, a hydroxyl group, an alkoxy group, an aryl groupand an acetoxy group, and wherein said aromatic ring of the naphthaleneseries formed by R1 and R2 forms an Alpha -naphthoxazole nucleus, a Beta, Beta -naphthoxazole nucleus, or a Beta -naphthoxazole nucleus, whereinsaid alkyl group for R3 and R4 is a methyl group, an ethyl group, a2-propenyl group, a hydroxyalkyl group, an acetoxyalkyl group, anaminoalkyl group, a carboxyalkyl group, a sulfoalkyl group, or anaralkyl group, wherein said methine groups for L1 and L2 represent CH-or
 6. The silver halide photographic emuLsion as claimed in claim 1wherein said sensitizing dyes are each present in said emulsion in anamount ranging from 1 X 10 6 mol to 5 X 10 3 mol per mol of silver andwherein the molar ratio of said carbocyanine dye to said merocyanine dyeranges from 1/10:1 to 5:1.
 7. A light sensitive photographic elementcomprising a support having at least one layer coated thereon of thesilver halide photographic emulsion of claim
 1. 8. A light sensitivephotographic element comprising a support having at least one layercoated thereon of the silver halide photographic emulsion of claim
 2. 9.The light sensitive photographic element as claimed in claim 7 whereinsaid support is a synthetic resin film, a paper, a polyolefin coatedpaper, a paper substitute, a glass plate, or a plastic plate.
 10. Thesilver halide photographic emulsion as claimed in claim 2 wherein saiddye of the general formula II is selected from the group consisting of11. The silver halide photographic emulsion as claimed in claim 2,wherein Y1 and Y2 each represents a sulfur atom.
 12. The silver halidephotographic emulsion as claimed in claim 2, wherein Y1 and Y2 eachrepresents a selenium atom.
 13. The silver halide photographic emulsionas claimed in claim 2, wherein Z1 and Z2 each represents the atomsnecessary to complete an aromatic ring of the benzene series.
 14. Thesilver halide photographic emulsion as claimed in claim 2, wherein Z1and Z2 each represents the atoms necessary to complete an aromatic ringof the naphthalene series.
 15. The silver halide photographic emulsionas claimed in claim 2, wherein the substituent on A is SO3M.
 16. Thesilver halide photographic emulsion as claimed in claim 2, wherein thesubstituent on A is COOM.
 17. The silver halide photographic emulsion asclaimed in claim 1, wherein the sensitizing dye combination consistsessentially of at least one of said dimethine merocyanine dyes and atleast one of said J-band type carbocyanine dyes.